Heart Murmur

Definition

A heart murmur is a sound made by turbulent blood flow in the heart. It sounds like whooshing or swishing with each heartbeat. Some adults and many children have incidental heart murmurs that are benign (harmless) and are not caused by abnormalities in the heart. However, some heart murmurs can signal an underlying heart problem.

Causes

Benign murmurs are caused by the normal flow of blood through the heart and large vessels near the heart. The murmur may come and go over time. Some things that can increase blood flow and cause a benign heart murmur to be heard include:

Endocarditis
—infection of the inner lining of heart valves and chambers (endocardium)

Rheumatic fever—inflammation and damage of the heart valves from poorly treated strep throat

Cardiac myxoma—a benign soft tumor within the heart (rare)

Risk Factors

Normal heart murmurs are more common in children 3-7 years old. Pregnant women are also at increased risk.

Risk factors for abnormal heart murmurs include:

Rheumatic fever

Atherosclerosis

High blood pressure

Autoimmune disease

Congenital heart defects or disease

Symptoms

Benign heart murmurs usually cause no symptoms. Patients with mitral valve prolapse sometimes complain of vague chest discomfort and other symptoms. It remains unclear whether or not the valvular abnormality is causing the symptoms.

Signs and symptoms of abnormal heart murmurs can include:

Rapid breathing or trouble breathing

Blue lips (cyanosis)

Lightheadedness

Chest pain

Rapid or irregular heartbeat

Exercise intolerance

Inability to gain weight in children

When Should I Call My Doctor?

If you think that you or your child has a heart murmur, you should see the doctor.

Diagnosis

Most benign heart murmurs are diagnosed during the course of a routine physical exam with a stethoscope. Some abnormal heart murmurs are also discovered this way. Other abnormal heart murmurs are discovered initially by their symptoms.

If you have high blood pressure or diabetes, follow your treatment plan.

Although not routinely recommended for every type of heart murmur, you may need to take antibiotics before and after some medical or dental procedures that could allow bacteria to enter your bloodstream. Ask your doctor if you need to take preventive antibiotics.

Revision Information

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.